/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.ray.streaming.state.backend;

import io.ray.streaming.state.backend.impl.MemoryStateBackend;
import io.ray.streaming.state.config.ConfigKey;
import java.util.Map;

/**
 * State Backend Builder.
 */
public class StateBackendBuilder {

  private static AbstractStateBackend getStateBackend(Map<String, String> config,
                                                      BackendType type) {
    switch (type) {
      case MEMORY:
        return new MemoryStateBackend(config);
      default:
        throw new RuntimeException(type.name() + " not supported");
    }
  }

  public static AbstractStateBackend buildStateBackend(Map<String, String> config) {
    BackendType type;
    if (config == null) {
      type = BackendType.MEMORY;
    } else {
      type = BackendType.getEnum(config.get(ConfigKey.STATE_BACKEND_TYPE));
    }

    return getStateBackend(config, type);
  }
}
